It's so kind of you to feed these stray cats!
I'm so sorry the cats fought yesterday and one cat's eye seems to be injured. The cloudiness you see in that eye could be caused by the third eyelid, which shows when there is an eye problem or general illness in the body.
It's important that the injured cat be seen in person by a vet, if you are able to pick it up and get it into a carrier. The eye could have been scratched in the fight and this caused infection, a corneal abrasion, or other serious condition, and that's why the cat has to be assessed and treated, immediately.
To try to keep the 'new' cat from fighting with your stray, again, try to place their food bowls far apart. Keep the bowl for the cat you've been feeding in the same place and place the bowl for the other cat around the other side of your house, if possible and show it the bowl.
If there's any way you can bring 'your' cat inside to stop the fighting, that would be the best solution to that problem; if the cat is too 'feral' to try that, you can keep trying.
The cat may very well lose the eye if it is not treated right away. Unfortunately, there's not much you can do at home; the only thing I can think of is to get some Terramycin ophthalmic ointment, if you can find it in any pet supply stores, feed stores, or order online with next day delivery.
Try your best to get this cat seen at a vet or ER vet center asap, if you can.
I hope all will be well with this kitty!
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